OVH supports DNSSEC with algorithm 13 through their API.
OVH Supports adding the DS record via their DNS Manager.
OVH API documentation for adding a DS record can be found here.
Note: You'll notice that as an output of this call, OVH will return a slightly different DS record. This is because OVH prefers to use SHA-1 over SHA-256, so after you enter in the DS record, OVH will recalculate the DS to use SHA-1. This will cause no problems with your website.